Comparing Float Valve Types Part 1 Vs Part 2

Imagine being awakened at night by the sound of an overflowing water tank, with the culprit being a seemingly insignificant float valve. What many don't realize is that these valves come in two distinct designs—Part 1 and Part 2—with differences that significantly impact water safety and regulatory compliance.

The most noticeable distinction between these float valves lies in their outlet positions:

• Part 1 Float Valves: Feature outlets at the bottom of the valve body. This older design is prone to creating siphon effects, potentially leading to water contamination.
• Part 2 Float Valves: Position outlets at the top of the valve body with a plastic nozzle directing water downward. This configuration prevents outlet submersion, effectively eliminating back-siphonage risks.

These valves are commonly found in attic tanks or expansion vessels, and understanding their design variations is crucial for proper selection.

The gradual elimination of Part 1 valves stems not just from design limitations but primarily from their non-compliance with modern water regulations. Current standards prioritize contamination prevention in water supply systems, an area where Part 1 valves demonstrate significant shortcomings.

Modern installations now mandate Part 2 valves as they incorporate critical backflow prevention. Their design ensures that even during valve failure, the nozzle remains above water level, maintaining system integrity and protecting against potential contamination.

The two valve types differ substantially in their water level adjustment capabilities:

• Part 2 Valves: Incorporate a locking adjustment collar that allows precise water level control through simple vertical float movement.
• Part 1 Valves: Require manual bending of the metal float arm for adjustments—a crude method that often leads to imprecise control and potential component damage.

The superior adjustability of Part 2 valves provides users with enhanced control and customization options for their water systems.

The regulatory preference for Part 2 valves addresses a critical contamination scenario: when a failed Part 1 valve allows tank water to backflow into the main supply. Part 2's elevated outlet position creates a physical barrier against this hazardous reverse flow, even during component failures.

This design philosophy exemplifies how modern engineering prioritizes fail-safe water protection through thoughtful mechanical solutions.

When selecting float valves, consider these factors:

• Regulatory Compliance: Always choose Part 2 valves for new installations or replacements
• Material Quality: Opt for corrosion-resistant materials like stainless steel or high-grade plastics
• Size Compatibility: Match valve diameter to existing pipework for optimal performance
• Water Conditions: Consider filtered models for areas with poor water quality

Industry data reveals a steady decline in Part 1 valve sales as Part 2 models dominate the market. User satisfaction surveys consistently rate Part 2 valves higher for their reliability, ease of adjustment, and longer service life.

This transition reflects growing consumer awareness of water safety standards and preference for advanced, regulation-compliant solutions in residential and commercial water systems.